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- Info
Agriculture and wildlife: ecological implications of subsurface irrigation drainage
| Author: |
Lemly, A. D. |
| Date: |
1994 |
| Periodical: |
Journal of Arid Environments |
| Link: |
http://www.srs.fs.usda.gov/pubs/ja/ja_lemly003.pdf
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| Abstract: |
Subsurface agricultural irrigation drainage is a wastewater with the potential to severely impact wetlands and wildlife populations. Widespread poisoning of migratory birds by drainwater contaminants has occurred in the western United States and waterfowl populations are threatened in the Pacific and Central flyways. Irrigated agriculture could produce subsurface drainage and wildlife problems in other countries because several of the factors contributing to toxic drainwater in the western U.S.A. (e.g. marine sedimentary basins with soils containing elevated concentrations of trace elements such as selenium and molybdenum; alkaline conditions that favor the formation of water-soluble forms of trace elements; soil salinization problems that require the use of irrigation to flush away excess salts), also occur in other arid regions of the world. Proposed agricultural irrigation projects should undergo a technical review to assess water demand and supply relationships, and to determine the potential for drainage problems. Environmental assessments should be made at existing irrigation projects to determine if subsurface drainage is present or could occur in the future. Anticipating and evaluating potential problems will allow changes to be made in irrigation practices for the benefit of agriculture and wildlife. The agricultural demands on water have reduced freshwater inflows and affected the quantity and quality of wetlands throughout the world for decades. Subsurface irrigation drainage is yet another threat to the precarious existence of many wildlife populations. |
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